/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package hivemall.sketch.bloom;

import java.io.IOException;
import java.util.Random;

import javax.annotation.Nonnull;

import org.apache.hadoop.hive.ql.metadata.HiveException;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.util.bloom.DynamicBloomFilter;
import org.apache.hadoop.util.bloom.Filter;
import org.apache.hadoop.util.bloom.Key;
import org.junit.Assert;
import org.junit.Test;

public class BloomAndUDFTest {

    @Test
    public void test() throws IOException, HiveException {
        BloomAndUDF udf = new BloomAndUDF();

        DynamicBloomFilter bf1 = createBloomFilter(1L, 10000);
        DynamicBloomFilter bf2 = createBloomFilter(2L, 10000);

        Text bf1str = BloomFilterUtils.serialize(bf1, new Text());
        Text bf2str = BloomFilterUtils.serialize(bf2, new Text());

        bf1.and(bf2);
        Text expected = BloomFilterUtils.serialize(bf1, new Text());

        Text actual = udf.evaluate(bf1str, bf2str);

        Assert.assertEquals(expected, actual);

        DynamicBloomFilter deserialized =
                BloomFilterUtils.deserialize(actual, new DynamicBloomFilter());
        assertNotContains(bf1, deserialized, 1L, 10000);
        assertNotContains(bf1, deserialized, 2L, 10000);
    }

    @Nonnull
    private static DynamicBloomFilter createBloomFilter(long seed, int size) {
        DynamicBloomFilter dbf = BloomFilterUtils.newDynamicBloomFilter(3000);
        final Key key = new Key();

        final Random rnd1 = new Random(seed);
        for (int i = 0; i < size; i++) {
            double d = rnd1.nextGaussian();
            String s = Double.toHexString(d);

            key.set(s.getBytes(), 1.0);
            dbf.add(key);
        }

        return dbf;
    }

    private static void assertNotContains(@Nonnull Filter expected, @Nonnull Filter actual,
            long seed, int size) {
        final Key key = new Key();

        final Random rnd1 = new Random(seed);
        for (int i = 0; i < size; i++) {
            double d = rnd1.nextGaussian();
            String s = Double.toHexString(d);
            key.set(s.getBytes(), 1.0);
            Assert.assertEquals(expected.membershipTest(key), actual.membershipTest(key));
        }
    }

}